She said she was disturbed months later, after Bakker moved to Sarnia, to discover that he’d returned to her street, this time living with Amanda Dumont and her four children.

Fleming’s insight into Bakker’s character and her heated conversation on the street with Dumont just a day before Dumont’s 20-month-old son, Ryker Daponte-Michaud, was found dead, was the latest twist in the shocking, sad case of child neglect.

Bakker, 27, and Dumont, 30, are charged jointly with criminal negligence causing death and separately charged with failing to provide the necessaries of life to the toddler.

He suffered second- and third-degree burns from scalding coffee to his back, genitals, waist and upper legs at least three days before his death. He was never taken to a doctor or hospital for any medical intervention.

On Tuesday, there was a steady parade of witnesses, including Dumont’s mother, Anne Daponte, who testified about her strained relationship with her daughter and her insistence that Ryker be taken to the hospital when her daughter told her the baby had been burned.

But Fleming’s testimony that will continue on Thursday could have a devastating effect on both defences.

After Bakker and Dumont moved in, Fleming said, she and Dumont began a “volatile” relationship. “There was a lot of yelling back and forth about Scott Bakker,” she said.

Fleming said there was no question in her mind Bakker and Dumont were living together.

The day before Ryker died, the tires on Dumont’s car were slashed. She tried to pin the crime on Fleming. The same day, as Dumont returned home by cab, Fleming confronted her on the street.

Dumont told her she had nothing to say, but Fleming testified she told Dumont that any problem she had with Dumont would be in person and not taken out on her car.

She told Dumont, that, as a mother, she understood the importance of having a car. “I would not go to that extent and be that low to do that to your vehicle,” she said she told Dumont.

Dumont said all she wanted

was a quiet, happy life with no drama. “I told her if she didn’t want drama on Penny Lane, you’re not going to get it living with Scott Bakker.”

That’s when Dumont told her Ryker was sick and she needed the car to take him to medical appointments.

Fleming testified she told Dumont that she had a fuelled-up vehicle and “please don’t hesitate to ask me. I’ll take you wherever you want to go.”

Dumont didn’t take her up on her offer, Fleming said.

Dumont’s mother, Anne Daponte, described how every phone call Dumont placed to her would be laced with anger and end in a hang-up.

Daponte said Dumont called to tell her that Ryker, the baby Daponte called Joey because she didn’t like his name, had been burned.

“I told her, ‘For goodness sake, you have to take him to the hospital,’ ” Daponte said.

But when Daponte said she couldn’t drop everything to drive from Watford to Strathroy, “she was angry, angry, angry at me.”

Three days later, a frantic Dumont called her and said Ryker was dead. Daponte said she drove to Strathroy, but couldn’t get into the house because of the police investigation.

At some point, Daponte said Dumont told her mother what happened to the baby.

“She told me that Joey was standing at the coffee table and he was getting his diaper changed and Scott left the room to get a fresh diaper and Joey pulled coffee down on himself,” she said.